Various conventional frequency modulated, continuous wave lidar systems exist. These lidar systems typically employ a laser source (i.e., laser), the selection of which requires a design trade off between speed of tuning and coherence length. Coherence length, in turn, impacts an effective range within which the lidar system is able to make accurate measurements. In other words, lasers capable of being tuned suffer from reduced coherence length and thus, reduced effective range. This presents a disadvantage for frequency modulated lidar.
In addition, these conventional lidar systems are typically unable to measure (i.e., detect and/or characterize) certain vibrations on a surface of a target over a broad band of frequencies, particularly where the vibrations may have sub-micron amplitudes at any frequencies within the band. Due to various lidar system constraints, primarily sampling rates and down conversion, these vibrations often appear as additive noise at frequencies other than their actual frequency of vibration.
What is needed are systems and methods for improving performance of lidar systems.